Word Cloud (詞雲) - Matlab

今天要總結的是 Word Cloud 最後一個部分了，用 Matlab 來建立 word cloud。Matlab R2018b 已經提供 wordcloud 函數能夠直接生成詞雲了。

>> Create Word Cloud via Matlab

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1) 準備文本。

很少說了，懶人繼續用上次那個 Word Cloud History.txt 的文本吧。

2) 讀取並清洗數據文本。

%read txt as a string
text = string(fileread('C:\Users\yuki\Desktop\WordCloudHistory.txt'));
%delete puchuation
punctuationCharacters = ["." "?" "!" "," ";" ":"];
text = replace(text,punctuationCharacters," ");
%convert a string to array
words = split(join(text));
%delete the words has less than 5 characters, which are problely stop words
words(strlength(words)<5) = [];
%change all words to lowercase
words = lower(words);

3) 計算詞頻並生成數組。

%calculate the frequencies for every word
[numOccurrences,uniqueWords] = histcounts(categorical(words));

4) 生成 word cloud。

figure
%set properties for word cloud
wordcloud(uniqueWords,numOccurrences,'Shape', "rectangle", 'MaxDisplayWords', 200);
title("Word Cloud History")

>> Notes

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1) Matlab 也有插件能夠直接生成詞雲，操做簡單，不用編程，哈哈。

2) 既然已經說了各類能夠建立詞雲的方法，那麼就順便總結一下什麼方法好用方便不花錢。

Tool		Easy Use		Free		Need Script
Python		Clear document, powerful text mining library		Yes		Yes
JavaScript		Need to extract array by own, and need to find a way to save the image		Yes		Yes
R		Clear document, powerful text mining library		Yes		Yes
Matlab		Clear document, interactive interface		No		Optional

>> Sample Code

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download here

>> Related Blogs

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1. Word Cloud (詞雲) - Python
2. Word Cloud (詞雲) - JavaScript
3. Word Cloud (詞雲) - R